Citigroup customers were told to upgrade to a newer Apple iPhone personal banking application after a security glitch was discovered during a routine security review.
The flawed mobile banking app may have saved personal account information such as account numbers, bill payments and security access codes in a hidden file on users’ iPhonesthe report said. Information may have also been saved on users' computers according to the report.
Citigroup notified customers in a letter dated July 20 about the security flaw. The bank is telling its customers to upgrade their apps to a new version, which corrects the problem and deletes any information that may have been saved on the iPhones or computers without their knowledge.
The bank also said it has no evidence that hackers have accessed any data on users' phones.
“We have no reason to believe that our customers’ personal information has been accessed or used inappropriately by anyone,” Citi spokesperson Natalie Riper said in a statement.
The report indicated there is growing concern about security challenges with wireless apps with potential leakages of confidential information.
Citi said its app for credit card customers was not affected by the security flaw, according to the Wall Street Journal, which first reported the story.
Citigroup shares were up more than 2 percent Monday on the New York Stock Exchange. Shares of Apple were down less than 1 percent.